Estimates of technically recoverable reserves were based on a regional assessment of the entire OCS that the US Minerals Management Service completed in 2006.

These estimates also include assessments of new areas identified for inclusion in the 2010-15 draft proposed 5-year OCS leasing program.

The numbers should be considered general indicators and predictors of oil and gas potential, said a report that MMS developed in response to a Feb. 10 order by US Interior Secretary Ken Salazar.

MMS noted new areas in the Atlantic, eastern Gulf of Mexico, Pacific and Alaska OCS were identified for inclusion in the draft proposed 5-year oil and gas program.

Salazar added 6 months to the public comment period and broadened its scope to include renewable and alternative energy sources. He also scheduled public meetings in each of the four OCS planning areas during April.

"Although leasing has not occurred in these areas for about 25 years, previous exploration has occurred in portions of these areas and some contain active leases with producing oil and gas fields. Updated research and exploration regarding the likely location of energy resources and environmental impacts are necessary to fill in data gaps," the report said.

Hydrocarbon endowmentMMS undertook the 2006 OCS assessment under a provision of the 2005 Energy Policy Act. Mean estimates of the total OCS hydrocarbon endowment were 115 billion bbl of oil and 633.6 tcf of gas, or a total of 228.2 billion boe. More than 18% has been produced and another 11% is contained within various resource categories representing near-term and mid-term production.

"Notably, even after more than 50 years of exploration and development on the OCS, 70% of the mean boe total endowment is represented by undiscovered resources. More than half of this potential exists in areas of the OCS outside of the Central and Western Gulf of Mexico," the report noted.

Of the estimated undiscovered technically recoverable resources on the OCS, the largest amounts are in the Gulf of Mexico (41.21-49.11 billion bbl of oil and 218.83-249.08 tcf of gas) and offshore Alaska (8.66-55.14 billion bbl and 48.28-279.62 tcf), said the 2006 assessment.

For the 2010-15 draft proposed program, estimated economically recoverable resources under prices of $60/bbl and $6.41/Mcf totaled 52.16 billion bbl and 200.85 tcf. The amounts rose to 64.85 billion bbl and 270.43 tcf at $110.74/bbl and $11.74/Mcf, and 70.79 billion bbl and 307.04 tcf at $160/bbl and $17.08/Mcf.

The report also examined potential contributions from wind, wave, and tidal energy operations on the OCS. The Atlantic OCS has the greatest renewable energy potential of the four planning areas, with offshore wind power likeliest to make a substantial contribution in the next 5-7 years, it said.

Atlantic concentration"Substantial wind resources exist offshore the Atlantic Coast, near high-energy demand centers. Strong wind resources also exist offshore California, Oregon, Washington, and Hawaii, but it appears that the majority of this resources likes in deep waters where technology constraints are potentially significant," the report said.

Alaska also has ocean areas with outstanding renewable energy resource potential, but they are not expected to be developed in the near term because of harsh weather their distance from high-energy demand centers, the report added.

It also identified several safety and environmental factors that could restrict OCS energy development. Oil spills were cited as a major concern but spill-prevention efforts are believed effective.

Understanding sea floor habitats will be important in leasing decisions for renewable and traditional energy resource development, the report said. Some information already has been gathered, but there are significant data gaps for a number of areas, it indicated.

"In some cases, exploration seismic surveys for oil and gas production, followed by required site-specific, high-resolution hazard surveys, could provide detailed information about the seabed with regard to drilling hazards as well as for evaluating benthic habitats."

Coastal impactsThe report also cited coastal impacts ranging from wetland losses along the US Gulf Coast to heavily developed or protected Pacific Coast areas that reduce options for pipelines or utility corridors to support shore-based construction.

"While there are refineries and ports capable of supporting heavy industry, for the most part the Atlantic region lacks existing onshore infrastructure geared to supporting offshore activity. Additionally, a significant portion of the coast, except portions of South Carolina and Georgia, are either developed or are state or federally protected shorelines," the report said.

"Key challenges for renewable energy development common to all OCS areas include offshore space-use conflicts, artificial reef effects, habitat alteration, noise from pile driving, and effects from electromagnetic fields," the report said.

In addition to seismic surveys that will be necessary to close gaps in OCS oil and gas resource evaluation, the report said offshore renewable energy technologies are still developing so standardized protocols and technical design criteria are needed.

"The experience, knowledge and tools exist to ensure that offshore energy development is developed in a comprehensive and environmentally sound manner. By obtaining stakeholder input (locally and nationally), compiling existing information, and acquiring new data where needed, conducting objective analyses using monitoring data to manage adaptively, and applying the necessary mitigations and safeguards along the way, we can achieve our national energy, economic and environmental goals," the report said.